A CAPTCHA (an acronym for Completely Automated Public Turing test to tell Computers and Humans Apart) is a type of challenge-response test used in a computing environment to determine whether a user of a device is human. For example, a device may provide a challenge, based on a CAPTCHA, to another device and may receive a response to the challenge from the other device. Based on the response, the device may determine whether the user of the other device is human.